There are various types of welders on the market nowadays for use by the home handyman. In the main, such welders are of the electric arc type and are often sold in kits comprising a welder and a welding transformer for use, for example, in the repair of motor vehicle bodywork. Whilst such kits undoubtedly provide useful welding tools, the usual electric arc welder is far too fierce for modern day motor panels and the home mechanic is unlikely to weld together body panels successfully with such a welder. Such disadvantages could be overcome by using a spot welder but the normal type of spot welder requires access to the rear of the workpieces to be joined and this is sometimes not possible. Moreover, spot welding apparatus is very expensive and usually cumbersome.